P0308 on 2010-2015 Chevrolet Camaro: Cylinder 8 Misfire Causes and Fixes

What's Unique About the 2010-2015 Chevrolet Camaro

The 2010-2015 Camaro SS uses two different 6.2L V8 engines: the LS3 in manual cars and the L99 in automatics. The L99 engine is equipped with Active Fuel Management (AFM), which deactivates cylinders to save fuel. A critical point of failure on L99 engines is the valve lifters; the special AFM lifters are known to fail, but the standard lifters can also fail due to related oiling issues. While cylinder 8 is NOT an AFM cylinder (the AFM cylinders are 1, 7, 6, and 4), a P0308 code on an L99 is frequently a sign of a collapsed standard lifter, which is a major mechanical repair. This specific type of widespread lifter issue does not affect the LS3 engine.

Symptoms You May Notice

• Rough or shaking idle
• Hesitation or stumbling during acceleration
• Noticeable loss of engine power
• Flashing or solid Check Engine Light
• "Service StabiliTrak" message may appear on the 🎬 Watch: Common causes for the Service StabiliTrak warning light. dash
• Smell of raw fuel from the exhaust
• Audible ticking or tapping noise from the engine, especially on L99 models, indicating a possible lifter issue

Most Likely Causes

1. Failed Ignition Coil 🔴 High Probability → Shop Ignition Coil Heat in the engine bay, particularly for the rear cylinders like #8, can shorten the life of ignition coils.
   How to confirm: Swap the cylinder 8 ignition coil with another cylinder (e.g., cylinder 6, which is the next one forward on the same passenger bank). Clear the codes and drive. If the code changes to P0306, the coil is bad. This is the most common and effective first diagnostic step.
   Typical fix: Replace the faulty ignition coil. It's often recommended to replace the spark plug at the same time.
   Est. part cost: $30-$70
2. Worn or Fouled Spark Plug 🔴 High Probability → Shop Spark Plug
   How to confirm: Remove the spark plug from cylinder 8. Inspect it for wear, carbon buildup, oil fouling, or damage to the electrode or ceramic insulator. A gas-fouled plug was found in one owner's case. You can also swap it with another cylinder's plug to see if the misfire follows.
   Typical fix: Replace the spark plug. It is best practice to replace all 8 spark plugs at the same time 🎬 See this walkthrough on how to replace your Camaro's spark plugs. for even performance, especially if they are near their service interval.
   Est. part cost: $8-$20 per plug
3. Bad Spark Plug Wire 🟡 Medium Probability → Shop Spark Plug
   How to confirm: Visually inspect the wire for any signs of damage, arcing (white marks), or burning near the manifold/headers. Check that the boot is securely connected to both the spark plug and the ignition coil. A loose plug wire is a surprisingly common cause. You can also test the wire's resistance with a multimeter.
   Typical fix: Replace the faulty spark plug wire. It's often sold as a complete set of 8.
   Est. part cost: $50-$100 for a set
4. Failed Valve Lifter (L99 Engine Primarily) 🟡 Medium Probability The Active Fuel Management (AFM) system on the L99 V8 (automatics) is a known weak point. While cylinder 8 is not an AFM cylinder, the system's complexity and oiling requirements can lead to failures of both AFM and standard lifters. These lifters can collapse or become stuck, causing a persistent misfire.
   How to confirm: This is a more advanced diagnosis. After ruling out ignition and fuel issues, a compression test on cylinder 8 is necessary. A significantly lower reading points to a mechanical problem. A distinct ticking/tapping noise from the passenger-side valve cover area is a strong indicator. Professional diagnosis is often required.
   Typical fix: Requires replacing the faulty lifter(s). If the camshaft lobe is damaged, it must also be replaced. Many owners opt to perform an 'AFM delete' at this time, replacing all AFM components (cam, lifters, valley cover) with standard LS3 parts to prevent future failures.
   Est. part cost: $400-$2000+ for parts, depending on whether an AFM delete is performed.
5. Clogged or Failed Fuel Injector ⚪ Low Probability → Shop Fuel Injector
   How to confirm: Use a mechanic's stethoscope or a long screwdriver to listen to the injector on cylinder 8; it should have a consistent clicking sound. For a more definitive test, swap the injector with another cylinder (e.g., cylinder 6) and see if the misfire code moves to P0306.
   Typical fix: Replace the faulty fuel injector.
   Est. part cost: $50-$120

Rare But Worth Checking

• Broken Valve Spring or Bent Pushrod: Aggressive driving or high mileage can lead to valvetrain failures. One owner on a Camaro5 forum documented a P0308 that, after extensive diagnosis including swapping ignition and fuel parts, was ultimately caused by a broken pushrod on cylinder 8. This requires removing the valve cover to inspect the rocker arms, springs, and pushrods.
• Intake Manifold Gasket Leak: → Shop Engine Intake Manifold A vacuum leak isolated to the intake runner for cylinder 8 can lean out the mixture and cause a misfire. This can be tested by spraying carb cleaner or using a smoke machine near the cylinder 8 intake runner with the engine running and listening for a change in idle speed.

Diagnosis Steps

1. Confirm the active code is P0308 using an OBD-II scanner. 🎬 Watch: A quick breakdown of the P0308 code and fixes. Note if the Check Engine Light is solid or flashing.
2. Note the cylinder location: On the LS3/L99, cylinders are numbered 1-3-5-7 on the driver's side (front to back) and 2-4-6-8 on the passenger's side (front to back). Cylinder 8 is the rearmost cylinder on the passenger side.
3. Swap the ignition coil from cylinder 8 with the coil from cylinder 6 (passenger side, one cylinder forward). Clear the codes and run the engine. If the code changes to P0306, the ignition coil is faulty.
4. If the misfire remains on cylinder 8, inspect the spark plug wire for damage and ensure it's securely connected at both ends. A loose wire is a common fix.
5. Remove and inspect the spark plug from cylinder 8. Look for excessive wear, fouling (gas or oil), or cracks in the white porcelain insulator. Replace if necessary.
6. If ignition components are good, check the fuel injector. Listen for a steady clicking sound. If in doubt, swap the injector with another cylinder to see if the misfire follows.
7. If the misfire persists, a mechanical issue is likely. For L99 engines, a failed lifter is a primary suspect. For both L99 and LS3, a broken valve spring or bent pushrod is possible.
8. Perform a compression test on cylinder 8. A healthy LS engine should show 120-150 PSI or more, with minimal variation between cylinders. A significantly lower reading points to a mechanical problem.
9. If compression is low, remove the passenger-side valve cover to visually inspect the valve springs, rocker arms, and pushrods for cylinder 8. A broken spring or a loose, wobbly rocker arm (indicating a collapsed lifter or bent pushrod) will be visible.

Parts You'll Likely Need

• Ignition Coil (OEM #12611424) — Ignition coils are a very common failure point for single-cylinder misfires and are easy to replace.
  Trusted brands: ACDelco, Delphi, NGK
  OEM price range: $40-$60
  Aftermarket price range: $25-$45
• Spark Plug (OEM #41-110 (Iridium)) — Spark plugs are a routine maintenance item and the first thing to check. A worn or fouled plug cannot create a strong enough spark.
  Trusted brands: ACDelco Iridium, NGK Iridium
  OEM price range: $10-$15
  Aftermarket price range: $8-$12
• Spark Plug Wire Set (OEM #92242549) — The wire carries high voltage to the plug. Damage from heat or a loose connection will cause a weak or no-spark condition.
  Trusted brands: ACDelco, MSD, Taylor
  OEM price range: $70-$90
  Aftermarket price range: $45-$75
• Standard Hydraulic Roller Lifter (OEM #12648846) — For L99 engines with a confirmed mechanical failure on cylinder 8, this is the correct non-AFM lifter needed for the repair. It is also used in the LS3.
  Trusted brands: ACDelco, Sealed Power

Related Codes That Often Appear With This One

• P0300 — If the misfire is intermittent or other cylinders are also misfiring, a P0300 (Random/Multiple Cylinder Misfire) may be stored alongside P0308.
• P0358 — This code specifically indicates a fault in the ignition coil 'H' (cylinder 8) primary or secondary circuit, strongly suggesting the coil or its wiring is the root cause.
• P0208 — This code points to a fault in the cylinder 8 fuel injector circuit. If you see this with P0308, the fuel injector or its wiring is the likely culprit.

Technical Service Bulletins (TSBs) & Recalls

• PIP5163A: A GM bulletin regarding investigation of engine misfires, oil consumption, and cylinder damage. While not a direct fix, it is part of the diagnostic trail for these symptoms.
• Bulletin #PIP4138R: A manufacturer bulletin for vehicles with a Service Engine Soon lamp, engine misfire (DTCs P0300-P0308), and/or engine noise. It advises technicians to check for a worn camshaft lobe and/or lifter if standard diagnostics do not isolate the cause.
• Bulletin #PIP5628G: This bulletin provides information to be provided to TAC to assist in diagnosing vehicles presenting with misfires and DTC codes P0300 - P0308.

Platform-Specific Known Issues

• On L99 engines (automatics), failure of valve lifters is a known issue that can cause a P0308 code. While cylinder 8 is not an AFM cylinder, the entire valvetrain, including standard lifters, can be affected by oiling problems sometimes associated with the AFM system.

Mechanic-Grade Diagnostic Values

• Ignition Coil Primary Resistance — expected: 0.4 to 0.6 ohms. Failure: A reading outside this range, or significantly different from other coils, indicates a faulty coil.
• Ignition Coil Secondary Resistance — expected: 5,000 to 7,200 ohms (5.0kΩ - 7.2kΩ). Failure: A reading outside this range suggests the coil's secondary winding is compromised.
• Fuel Injector Resistance (High Impedance) — expected: ~12.0 ohms. Failure: A reading of 'OL' (open loop/infinite resistance) means the injector coil is broken. A reading near zero indicates a short. All injectors should measure within ~0.5 ohms of each other for consistency.
• Engine Compression — expected: 120-150 PSI or higher. Failure: A reading significantly below this range, or more than 15-20% lower than other cylinders, points to a mechanical issue like worn piston rings, a bad valve, or a failed lifter preventing the valve from closing.

Scan Tool Commands That Help

• GM GDS2 / Tech2: Cylinder Power Balance Test — This function allows a technician to individually disable fuel injectors for each cylinder while monitoring the RPM drop. If disabling cylinder 8 causes little or no change in engine RPM compared to other cylinders, it confirms that cylinder 8 is not contributing power, helping to isolate the misfire without swapping parts.
• GM GDS2 / Tech2: Misfire Graphic / Misfire Data — Provides a real-time and historical count of misfire events per cylinder. This is crucial for confirming that the misfire is isolated to cylinder 8 and for verifying that the repair has been successful by observing zero misfire counts on a test drive.

Wiring & Ground Locations

• Cylinder 8 Ignition Coil Control — Pin 33 on the X2 (Gray/Rear) ECM connector.. This is the specific pin on the Engine Control Module that sends the signal to fire the ignition coil for cylinder 8. A voltage or continuity test at this pin can diagnose a wiring fault between the ECM and the coil.
• Cylinder 8 Fuel Injector Control — Pin 34 on the X2 (Gray/Rear) ECM connector.. This pin on the ECM controls the ground signal for the cylinder 8 fuel injector. Testing this circuit is necessary when a fuel injector fault is suspected for P0308.
• G100 (V8) — On the lower right side of the engine block, above the starter solenoid.. This is a primary engine block ground. A loose or corroded connection here can cause numerous electrical issues, including weak spark or erratic sensor readings that could lead to a misfire.
• G110 (V8) — Attached to the rear of the driver's side cylinder head.. This is a critical ground for the PCM and ignition system. Forum members report that a loose G110 can cause rough idle, flickering lights, and other PCM-related issues that could be misdiagnosed.
• Ignition Coil Harness Grounds — Ring terminals at the back of each cylinder head.. These grounds are specifically for the ignition coils. A loose or poor connection on the passenger side head could directly impact the performance of the cylinder 8 coil.

Real Owner Repair Stories

• YouTube user comment on a Ram 1500 P0308 video, applicable to the mechanical failure mode. (2002 Dodge Ram with 225k miles (illustrates a common V8 lifter failure)) — Check engine light, ticking noise, P0308 code, loss of power.
  ❌ Tried (didn't work) Shop quoted an $8500 engine replacement., Friends suggested a long block rebuild., Standard advice to replace spark plugs did not apply.
  ✅ What actually fixed it The owner found a video describing a failed lifter causing the rocker arm to come off. Upon removing the valve cover, he found the cylinder 8 rocker arm had indeed fallen off. He replaced the faulty lifter and rocker arm for a total cost of $115, completely resolving the P0308 code and saving the engine.

OEM Part Supersession History

• 12570616 (Marked on original square coils) → 12611424 (ACDelco D510C) — GM consolidation and updates to the part.
  Heads up: The L99 (automatic) typically uses the square coil (12611424/D510C), while some LS3 (manual) models used a round coil (12573190). While they may be interchangeable with harness modification, it is critical to replace with the same style to ensure fitment of the harness connector and mounting bracket.

Model Year Variations Within This Range

• 2010-2015: The L99 engine (automatic) used square-style ignition coils (P/N 12611424), while the LS3 (manual) often used round-style coils (P/N 12573190). The wiring harnesses are different between the two styles. It is crucial to identify which coil type is on the engine before ordering a replacement.
• 2012-2015: Starting in 2012, V6 models received the updated LFX engine, and SS models received an improved FE4 rear suspension. While not directly related to a P0308 cause, it's a notable mid-generation update. The core LS3/L99 engine architecture and its common misfire causes remained consistent from 2010-2015.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• Torque Converter Shudder (Automatic) 🟠 Medium — Commonly reported between 40-50 mph, can feel like a misfire. A TSB was issued for this. (Ref: TSB exists, owners should check with a dealer.)
• AFM Lifter Collapse (L99 Engine) 🔴 High → Shop Engine Valve Lifter — A well-documented problem on L99 engines, leading to ticking noises and misfires. Can occur at various mileages. (Ref: Multiple TSBs address related symptoms like oil consumption and misfires.)
• Premature Timing Chain Wear 🔴 High → Shop Engine Timing Chain — More prevalent on V6 models, but has been reported on V8s, particularly earlier 2010-2012 models, sometimes linked to faulty oil change alerts. Can lead to catastrophic engine failure.
• Oil Cooler Coolant Leak 🟠 Medium — A failed gasket can cause a coolant leak on the driver's side of the engine, typically after 50,000 miles. (Ref: GM Service Bulletin PIP4735D)
• Ignition Switch Recall 🔴 High — Part of a massive GM recall. The driver's knee could bump the key fob, causing the engine to shut off while driving. (Ref: NHTSA Recall No. 14V346)

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: For expensive, non-wear items like a complete cylinder head assembly (if the original is damaged beyond repair) or engine covers. A used ignition coil from a low-mileage donor can be a cost-effective diagnostic tool to confirm a failure before buying new, but it's not recommended as a permanent fix.

Donor-vehicle mileage cap: roughly under 50000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• For ignition coils, check for cracks in the plastic housing or corrosion on the electrical pins.
• For mechanical parts like cylinder heads, look for signs of overheating (discoloration), warping (check with a straightedge), or obvious damage to valve seats or combustion chambers.
• Verify the donor vehicle's history if possible to avoid parts from a vehicle that had its own engine problems.

OEM-only on this vehicle (don't cheap out):

• Valve Lifters: Given the high failure rate of even OEM lifters (especially AFM lifters on the L99), using aftermarket lifters is a significant risk. Stick with ACDelco for replacements. If performing an AFM delete, use proven LS3 components.
• Engine Control Module (ECM): A used ECM will require reprogramming by a dealer or specialist to match the vehicle's VIN and security settings, often negating any cost savings.

Aftermarket brands forum-validated for this vehicle:

• Ignition Coils: Delphi, NGK (Often OEM suppliers).
• Spark Plugs: ACDelco Iridium, NGK Iridium.
• Spark Plug Wires: ACDelco, MSD, Taylor.

Brands owners have reported issues with on this vehicle:

• Unbranded/generic ignition coils and sensors: Forum discussions are filled with stories of cheap, no-name ignition coils from online marketplaces failing within weeks or months, or being dead on arrival.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P0300 — A random or multiple cylinder misfire code that often appears alongside P0308 during high-performance driving or general ignition failure.
• P0306 — The code that would appear if a faulty ignition coil or fuel injector from cylinder 8 is moved to cylinder 6 during the diagnostic swap process.
• P0302 — Another passenger-side bank misfire code; cylinders 2, 4, 6, and 8 all share the same bank and can be affected by similar heat-related ignition failures.

Frequently Asked Questions